Cooling plates for a metallurgical furnace, also called staves, are well known in the art. They are used to cover the inner wall of the outer shell of the metallurgical furnace, as e.g. a blast furnace or electric arc furnace, to provide: (1) a heat evacuating protection screen between the interior of the furnace and the outer furnace shell; and (2) an anchoring means for a refractory brick lining, a refractory guniting or a process generated accretion layer inside the furnace. Originally, the cooling plates have been cast iron plates with cooling pipes cast therein. As an alternative to cast iron staves, copper staves have been developed. Nowadays most cooling plates for a metallurgical furnace are made of copper, a copper alloy or, more recently, of steel.
A copper cooling plate for a blast furnace is e.g. disclosed in German patent DE 2907511 C2. It comprises a panel-like body having a hot face (i.e. the face facing the interior of the furnace) that is subdivided by parallel grooves into lamellar ribs. The grooves and ribs, which preferably have a dovetail (or swallowtail) cross-section and are arranged horizontally when the cooling plate is mounted on the furnace wall, to anchor a refractory brick lining, a refractory guniting material or a process generated accretion layer to the hot face of the cooling plate. Drilled cooling channels extend through the panel-like body in proximity of the rear face, i.e. the cold face of the cooling plate, perpendicularly to the horizontal grooves and ribs.
Such cooling plates are mounted in a plurality of rings against the furnace wall, wherein the rear faces of the cooling plates are directed towards the furnace wall. Because the furnace wall is generally rounded and the cooling plates are in principle planar, a space exists between the furnace walls and the cooling plates. This space is generally filled with backfilling concrete. Gaps are also present between the edge faces of neighboring cooling plates. These gaps are generally also filled with the backfilling concrete.
Generally, a refractory brick lining, a refractory guniting material or a process generated accretion layer is then provided against the front face of the cooling plate to form a protective layer. This protecting layer is useful in protecting the cooling plate from deterioration caused by the harsh environment reigning inside the furnace. At the same time, the protecting layer also protects the backfilling concrete in the gaps between cooling plates from deterioration. In practice, the furnace is however also occasionally operated without this protective layer, resulting first of all in the erosion of the backfilling concrete in the gaps. These gaps then contribute to a particularly uneven erosion of the cooling plates.